I have a specific machine, a Rotrics DexArm. This machine has the origin in the middle of the page. As I can see, there is no option to set the page to have 0 at its center/middle of an axis. How can I tell LightBurn that my machine has a workspace of [-100;100] instead of [0;200] when the work area is 200?
I understand what is possible to do with “Job origin”, but this defeats the “Print & Cut” capability.
Fortunately, the machine is able to set its origin to somewhere else, but this makes the setup both complicated and unsure (move to machine origin, set to 0, move to -100;-100, set to 0, move back to 100;100). Until now, I have not been able to properly do a print & cut, it’s always off by some distance, although the scale look roughly okay for what I can see.
Thanks for the link. This is also mostly what I do right now. But let’s be honest, trying to get everything right when the coordinates are upside down, offset, or both is quite complicated if the display doesn’t help a bit. Having the grid align to [0,0] would really be helpful!
Meanwhile, I think I’ve also overlooked a feature of my particular machine, and I should test more but I think that this is the reason why the print & cut is failing. The DexArm has different “heads” that can be mounted and it is important that the software knows which head is mounted on or the conversion between cartesian coordinates and the joints rotation of the arm will be incorrect, and this doesn’t translate to a simple linear offset, but to incorrect scale and distortion.
So, although this is a bit off-topic here, if anyone lands here looking for this issue with the DexArm, here is how I set it up:
Set workspace to X300, Y210mm in the machine properties.
Power the arm and open the “Console” view
Send M888 P1 to set the end effector to laser module
Send M1112 to place the arm at its factory origin (0;300)
Send G92 X150 Y125 to shift the arm’s origin to a position that maximizes the working area
(Optional it seems) Send M2000 to tell the arm that G0 shall be also linear movement (but Lightburn seem to properly send G0/G1 commands depending on the need).
Still (back to on-topic) I would love that the grid representation on Lightburn shows something that makes sense for this kind of machine. Indeed, I understand that a 0,0 on a corner makes sense for a cartesian (“square”) machine, but in my setup there is no such thing as “a corner”.
Print & cut requires that you be using Absolute Coordinates which you’re not able to use because of the situation with your coordinate system. You’ll need to get that sorted before print & cut can work reliably.
I’m confused. The link explains how to get your entire coordinate system into a positive space. That means one of the corners of your laser would be 0,0. That doesn’t sound like what you described.
Can you describe the challenge in setting this up? Will help to understand what alternatives might exist. There are a number of things in LightBurn that require the use of Absolute Coordinates to properly take advantage of them.
I didn’t realize it was an OOTB commercial machine.
There’s no frame but I don’t see what would prevent this from having a positive only coordinate system.
As a side note I didn’t realize that Marlin had an Inverse Kinematics system that could handle a robot arm like this. I knew it could manage delta printers but not generic robot arms.
